10th Class Mental Ability Analytical Reasoning Analytical Reasoning

This chapter is based upon the counting of various geometrical figures in a given complex figure.

EXAMPLE

1.         Count the number of triangles in the given figure.

(a) 14                            (b) 15             

(c) 16                            (d) 17

Explanation (c):

Let us label the given figure as shown in the adjoining figure.

Triangles made up of one segment: ANH, AOH, LBN, MCO, BDI, CEI, IDJ, IEJ.

These are 8 triangles.

Triangles made up of two segments: ABI, ACI, IFK, IGK, ANO, IDE.

These are 6 triangles.

No triangles made up of 3 segments.

Triangles made up of 4 segments: ABC, IFG.

These are 2 triangles.

Total number of triangles

Thus. the given figure consists of 16 trianales in all.